The invention relates to compositions, methods, and apparatuses for improving the production and recycling of antimicrobial fluids used to treat raw meat and poultry in meat and poultry slaughter and processing facilities. Fresh food animal products, including raw meat and poultry, are susceptible to contamination by microorganisms that contact meat surfaces immediately after slaughter and evisceration, including organisms in the gastrointestinal tracts which can be transferred during processing. Contaminating microorganisms include bacteria such as Salmonella and Campylobacter species, Listeria monocytogenes, Escherichia coli and other coliforms, and other enteric organisms. Once bacteria such as Salmonella contact tissue surfaces, they rapidly attach and are difficult to remove even with chlorine disinfectant permitted for use in poultry sprays and chill tanks. In beef processing, for example, a particularly virulent strain of E. coli, denoted O157:H7, reportedly contaminated hamburger meat sold by a fast-food chain and caused several deaths in the U.S. in 1993.
The problems created by Salmonella and Campylobacter bacteria in poultry products are particularly noteworthy. The presence of these organisms in food are serious dangers which impose significant costs and dangers. Improper cooking and physical transfer of the bacteria to food handling surfaces and thereafter to other foods result in the spread of the microorganisms, can cause gastrointestinal disorders and, in some cases, death.
Breeders, hatcheries, feed ingredient suppliers, farms, processors, and distributors have all been implicated as contributors to Salmonella contamination in chickens and turkeys (Villarreal, M. E., et al., J. Food Protection 53: 465-467 (1990)). Contamination of but a few birds can lead to broader range contamination of other birds and cross-contamination to carcasses. Bacterial proliferation and other signs of spoilage can be delayed by refrigeration, but there is a limit to the degree of refrigeration that can be imposed on meat products, short of freezing the meat, and some bacteria such as psychrophiles can survive and even flourish at temperatures approaching the freezing point. It is thus preferable to control and destroy pathogenic and other microbial contaminants during processing to reduce the number of organisms on the meat.
Poultry processing is similar to the processing of other meat animals. Briefly summarized, caged birds arrive by truck at the processing plant. Typically, the birds are not fed for at least one to four hours before slaughter to allow the bird's intestinal tract to clear, thereby lowering the risk of fecal contamination during subsequent processing. The birds are hung by their feet on shackles in a dressing line, stunned and bled via throat cuts. After bleeding and while still hung, the birds are scalded, plucked and transferred to an evisceration line, where they are manually or mechanically eviscerated, inspected and spray-washed. The spray may contain chlorine or other approved as a disinfecting agents. Historically, the last step of the process has been chilling in a hydro-chill tank, by movement through a counterflow of cold water containing chlorine or other approved antimicrobial agent are chilled, which usually takes about 45 minutes to one hour in a typical many-thousand gallon tank. The carcasses may additionally pass through a post chill spray, drench or dip antimicrobial treatment before being rehung, packaged or further processed into parts, other value-added products including but not limited to ground, mechanically separated and subsequently refrigerated or frozen.
Salmonella, Campylobacter and other organisms can survive the scalding process, which involves temperatures of about 50° C. to 58° C. Though cross-contamination can occur during any stage of processing, the major problems arise during and after evisceration when microorganisms are freed from the intestinal tract and transferred to other tissue surfaces. For example, the water becomes contaminated with organic matter and microbes from meat, and other organic matter provides nutrients for microbial growth over time or through additional use. The microbes can grow and contaminate additional meat, poultry, and equipment. Processing water can also serve as a source of contamination and cross-contaminate to other meat carcasses if organism in the water are not removed, inactivated or otherwise controlled.
A number of mechanisms have been attempted to address this problem. Such mechanisms include the application of chlorine, chlorine dioxide, peroxyacetic acids, GRAS acids, organic acids and mixtures thereof, octanoic acid, acetic acid, acidifed sodium chlorite, carnobacterium maltaromaticum stain CB1; cetylpyridinium chloride; citric acid; 1,3 di-bromo-5,5-dimethylhydantoin; citric acid, phosphoric acid, and hydrochloric acid mixtures; lactic acid; lactoferrin; lauramide arginine ethyl ester; nisin, oZone; hydrogen peroxide; peroxyacetic acid; peroxyoctanoic acid; potassium diacetate; lactic acid and acidic calcium sulfate mixtures; lactic acid, acidic calcium sulfate, and propionic acid mixtures; lactic acid, calcium sulfate, and sodium phosphate mixtures; sodium metasilicate; trisodium phosphate; or combinations thereof. An example of a suitable commercially available antimicrobial solution includes, but is not limited to: irradiation, trade designated SANOVA® acidifed sodium chlorite, available from Ecolab, Incorporated, Saint Paul, Minn.; and high pressure pasteurization applied during various stages of the meat/poultry handling process. As described in U.S. Pat. Nos. 7,887,850, 6,475,527, 6,761,911, 6,063,425, 5,830,511, and 5,389,390, the use of metal chlorites/chlorates are a particularly effective strategy for reducing or eliminating microbiological contamination of raw meat and poultry.
An impediment to the use of such metal chlorites/chlorates however is the cost and expense of producing and applying them. Metal chlorites/chlorates typically are acidified to a very narrow pH range to obtain a specific pKa value and to be highly selective regarding which chlorine species are produced. Efficient in situ maintenance of such conditions is an ongoing challenge in the industry. Moreover this complexity has proven to make the re-use of already used metal chlorite/chlorate solutions extremely difficult. As a result the cost of applying metal chlorite/chlorate antimicrobial solutions is much higher than is optimal.
Thus there is clear utility in novel methods, chemicals, and apparatuses for the production and re-use of antimicrobial fluids used to treat raw meat and poultry in meat and poultry slaughter and processing facilities. The present invention addresses these needs and provides further related advantages.
The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 CFR § 1.56(a) exists.